berhe32 Hi there. Goodybags last for one calendar month.
If the Goodybag you bought has an incorrect expiry date, please raise an agent case HERE and they (giffgaff staff) will look into the discrepancy for you.
If you raise a case with an agent about your Goodybag expiry date issue, you can view agent replies on your account dashboard, under the Messages section. Agents aim to reply to questions within 24 hours.